“Brexit could harm the UK’s wildlife and farming, according to a cross-party committee of MPs, with key protections left as ineffective “zombie legislation” and farmers facing a “triple jeopardy” of lost subsidies, export tariffs and increased competition.

A new report from the environmental audit select committee warns that many of the rules governing food production and the environment in the UK come from EU law and that weakening of these rules would damage the countryside and reduce the viability of farms, food security and safety.

The MPs said that for the government to meet its manifesto commitment to “be the first generation to leave the environment in a better state than it found it”, ministers must commit to passing a new Environmental Protection Act before it triggers article 50 and starts the formal process of leaving the EU.

The MPs said it was concerning that the environment secretary, Andrea Leadsom, gave no reassurance that farmers would receive subsidies after 2020. But the report also recommended that if a new subsidy regime was put in place, it should focus less on direct income support to farmers and more on delivering public goods, such as preventing flooding, tackling climate change and boosting wildlife.

Attenborough urges UK to use Brexit to improve wildlife protections
“Changes from Brexit could put our countryside, farming and wildlife at risk,” said Mary Creagh, chair of the environmental audit committee (EAC). “Protections for Britain’s wildlife and special places currently guaranteed under European law could end up as ‘zombie legislation’, even with the great repeal bill.”

Creagh said food, animal welfare and environmental standards had to be maintained as the UK seeks new trade deals with other countries. “The government must not trade away these key protections [and] it should also give clarity over any future farm subsidies.”

There are about 800 pieces of EU environmental legislation, covering wildlife and habitats, water quality, farming, food and fisheries. The government’s great repeal bill intends to transpose all those rules into UK law, but Leadsom told the EAC that about a third would be difficult to transpose.

The EAC said that, without pre-emptive action, these rules would end up as “zombie legislation”, with no body to enforce them, no updates and easily eroded by ministers via parliamentary statutory instruments, which receive minimal scrutiny from MPs.

The EU’s common agricultural policy provides £3.5bn a year in subsidies to UK farmers, making up more than half of their income, and the MPs said Brexit posed a “triple jeopardy” for farmers. Firstly the loss of subsidies would threaten the viability of some farms. Secondly, new export tariffs would cut farm incomes and, thirdly, new trading relationships could lead to competition with nations with lower animal welfare, food safety and environmental standards.

If the UK chooses not to be part of the EU single market, Tim Breitmeyer of the Country, Land and Business Association told the EAC that lamb exports to Europe would face tariffs of 30% and that beef export tariffs could be above 50%.

Even if the UK remained in the single market, the MPs said crucial EU directives such as those protecting habitats, birds and beaches, would have to be replaced as they are excluded from that agreement. “The government should safeguard protections for Britain’s wildlife and special places in a new Environmental Protection Act,” said Creagh.

A government spokeswoman said: “The UK has a long history of wildlife and environmental protection and we are committed to safeguarding and improving these, securing the best deal for Britain as we leave the EU.”

Vicki Hird, from Sustain, an alliance for better food and farming, said: “MPs have correctly identified a huge risk to the UK farming system and environment from Brexit and new trade agreements. Without environmental safeguards in place, [this] would mean major damage to the natural environment – the soils, pollinators and water – on which farming and everyone depends.”

Sam Hall, at the liberal conservative thinktank Bright Blue, said: “Brexit is an opportunity to improve the UK’s environment. The MPs rightly suggest new legislation could be needed to guarantee existing protections post-Brexit. But a new bill could go further and increase the level of ambition for the natural environment”, for example with tougher pollution controls.

Sam Lowe, at Friends of the Earth, said any changes to environmental protection must be subject to full parliamentary scrutiny and not made via statutory instruments: “No one voted to ‘take back control’ for the UK parliament, only to hand it straight over to a minister, brandishing a red pen, with the power to delete vital nature protections on a whim.”